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    Subject[PATCH 0/3] Replace kmalloc with vmalloc in seq_files
    When a seq_file is implemented with single_open, the show function will
    be called with a kmalloc'd PAGE_SIZE buffer. If the show function
    produces more data than can fit in the buffer, the buffer will be thrown
    away, and the show function will be called again with a buffer twice as
    large. This process repeats until the show function does not overflow
    the buffer, or kmalloc fails.

    seq_files are often used for debugging data. When the system is under
    memory pressure, and dumping debugging data starts trying to allocate
    large physically contiguous buffers, it often makes the problem worse.

    Since there is no need for a physically contiguous buffer, this patch
    set converts the kmalloc'd buffers into vmallocs. There are two
    seq_file users that kmalloc buffer and place it directly into the
    seq_file structure, later to be freed by seq_release. Convert those
    to call a new seq_reserve function that will do the correct allocation
    for them.

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      Last update: 2011-09-22 22:59    [W:0.018 / U:12.384 seconds]
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